In the past, as this sort of debris capturing device, for example, one as disclosed in Patent Literature 1 has been known. The debris capturing device 100′ is one that is, as illustrated in FIG. 43, adapted such that a filter member 3′ is attached to a fore end part of a wire 2′ inserted into a blood vessel, and for example, by arranging the filter member 3′ in a blood vessel during a medical operation or an operation for endovascular treatment, prevents a thrombus or the like detached during the operation from flowing toward a downstream side of the filter member 3′.
The filter member 3′ includes: a baglike filter 32′ formed of mesh fabric; and a ringlike elastic steel wire 31′ attached around an opening edge of the filter 32′. The filter 32′ can pass blood components such as blood cells and blood platelets and captures a thrombus and the like larger than such blood components, and in the blood vessel, the ringlike elastic steel wire 31′ is spread and arranged so as to make an opening of the filter 32′ orthogonal to blood flow.
The filter member 3′ is attached to the wire 2′ with four threads 4′. Each of the threads 4′ is, at one end part thereof, attached to a predetermined position of the wire, and at the other end part thereof, attached to a corresponding one of four positions of the ringlike elastic steel wire 31′. Also, in a state where the ringlike elastic steel wire 31′ is spread and formed in a circular shape, the threads 4′ are, as illustrated in FIG. 43, like parachute strings, formed in a conical configuration that spreads toward a downstream side of the blood flow as a whole.
Next, an example of the use of the debris capturing device 100′ in the case of, for example, relieving a stenosis in a carotid artery is briefly described.
First, a tubular body 1′ as illustrated in FIG. 44 is inserted into the blood vessel to position a fore end thereof at a base part of the carotid artery, i.e., at a site where the carotid artery branches from an aorta.
Then, a filter conveyance tube 12′ referred to as a conveyance sheath is protruded from the fore end of the tubular body 1′ through the inside of the tubular body 1′, and sent out until a fore end of the filter conveyance tube 12′ passes through a target stenosis part and is positioned at a periphery of the stenosis part. The filter member 3′ attached to the wire 2′ is stored in a fore end part of the filter conveyance tube 12′.
Subsequently, by pulling back only the filter conveyance tube 12′ while leaving the wire 2′ unmoved, the filter member 3′ is released from the filter conveyance tube 12′.
In doing so, the ringlike elastic steel wire 31′ is spread by an elastic restoring force thereof, and as illustrated in FIG. 43, the opening of the filter 32′ is arranged orthogonally to blood flow on a peripheral side of the stenosis part.
Then, after the filter conveyance tube 12′ has been pulled out of the body, a balloon catheter, a stent, or the like is conveyed to the stenosis part along the wire 12′ to perform treatment.
After that, when recovering the filter member 3′, an operation tube 13′ having at least a smaller fore end part than that of the filter conveyance tube 12′ is sent out along the wire 2′ to pull the respective threads 4′ into the operation tube 13′.
In doing so, the other end parts of the respective threads 4′, i.e., sites at which the respective threads 4′ are attached to the ringlike elastic steel wire 31′ are brought close to one another toward an opening of the operation tube 13′, and a contraction force acts on the ringlike elastic steel wire 31′.
As a result, as illustrated in FIG. 45, the ringlike elastic steel wire 31′ starts to bend alternately convexly and concavely at intermediate sites between the four points attached to the respective threads 4′.
Finally, the other end parts of the respective threads 4′ are gathered in a fore end opening part of the operation tube 13′, and as illustrated in FIG. 46, the ringlike elastic steel wire 31′ is folded into a substantially rodlike shape along an extending direction of the wire 2′ as a whole.
At this time, as illustrated in FIG. 46, parts of the ringlike elastic steel wire 31′ hold the fore end part of the operation tube 13′ from radially outside.
After that, as illustrated in FIGS. 46 and 47, the filter member 3′ is recovered by, while staying in a state where the folded filter member 3′ is attached to the fore end part, pulling the operation tube 13′ into the tubular body 1′ and pulling out the operation tube 13′.